Guard for punch-presses.



C. A. MACDONALD & M. P. DOUGHERTY.

GUARD FOR PUNCH PRESSES. APPLICATION FILED MAR. 9.19 14.

Patented Apr. 4,1916.

3 SHEETSSHEET I.

C. A. MACDONALD & M. P. DOUGHERTY.

' I GUARD FOR PUNCH PRESSES.

APPLICATION FILED MAR. 9" I914. Ll78fl68. Pmmmdmm4JMfi 3 SHEETS-SHEET 2.

C. A. MAcDONALD & M. P. DOUGHERTY. GUARD FOR PUNCH PRESSES;

APPLICATION FILED MAR. 9' 1914. 1,178,168,

Patented Apr. 4, 1916.

3 SHEETS-SHEET 3.

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CHARLES ADDISON MACDONALD AND MARTTN P. DOUGHERTY, OF ROCHESTER, NEWYORK.

GUARD FOR PUNCH-PRESSE S.

Specification of Letters Patent.

Application filed March 9, 1914. Serial No. 823,556.

To all whom it may concern:

Be it known that CHARLES ADDIS N MAC- DONALD and MARTIN P. DOUG ERTY,citi- Zens of the United States, residing at ROChStBI, in the county ofMonroe and State of New York, have invented certain new and usefulImprovements in Guards for Punch-Presses, of which the following is aspecification.

The object of this invention is to provide a guard for punch presses.This and other objects of the invention will. be illustrated in thedrawings, described in the specification and pointed out in the claimsat the end thereof.

In the accompanying drawings, Figure 1 is a front elevation of myimproved guard in position on a punch press. Fig. 2 is a perspectiveview of the actuating cam for one of the guards. Fig. 3 is a sideelevation of the guards in the frame of the press. Fig. at is a sectiontaken on-the line i -1 of Fig. 3. Fig. '5 is a detail view of the adjustme'nt slide for the actuator. Fig. 6 is a perspective view of theactuator., Fig. 7 is a detail view of the bolt for holding together theparts shown in Figs. 5 and 6. Fig. 8 is a diagrammatic view of the leverof the punch press and the connections between it and one ofthe guards.Fig. 9 is an elevation of the top portion of an ordinary punch press.Fig. 10 is a section on the line 1010" of Fig. 9 looking to the left.Fig. 11 is a section on the line 1(l*'-10 of Fig. 9 looking to'theright. Fig. 12 is a section on the line 1'2 12' of Fig. 9. Fig. 13 showsdetails of the small parts of the clutch.

in the accompanying drawings like reference numerals indicate likeparts.

in the drawings reference numeral 1 indicates the frame of the punchpress having the two upright members 2 and 3 between which travels theram t. The punch press is of the ordinary type having a shaft 67 at thetop thereof. which shaft is provided with an eccentric or crank (l bywhich the ram l of the press is driven. .On this shaft (37 is mounted torun looselyia balance wheel =31 having a clutch 5 through which clutchsaid balance wheel drivesthe-shaft. This clutch S is connected by a link0 to a lever 10 at the bottom of the machine nected the operating lever13 pivoted at HQ At the short endof this lever is connected the link 15,the opposite end of which is connected to the short end 16 of the arm 16pivoted on the stud 17 On the long arm of the lever 16 is mounted aguard plate 17, which is preferably of transparent material such ascelluloid, but may be of metal or other material. The guard 17 ismounted so as to swing in frontof the die on the bed of the punch press,which would ordinarily be located near the bottom of the parts shown inFig. 1 immediately behind the guard 17. These parts are so related thatwhen the operator presses down the treadle 18 on the lever 10 it raisesthe link f) and moves the guard 17 from the left to the right to theposition shown in Fig. 1. \Vhen the operator withdraws his foot so as torelease the treadle 18. the link 9 is drawn down by the spring 19 whichis attached to the lcv at one end and the frame of the machine at theother end and causes the guard 17 to move to the left to the positionshown in Fig. 1.

If the operators hand is in contact with the die when the treadle isthrown, the parts heretofore described will operate to knock or push hishand and his arm out of the road and out of danger the speed with whichthe guard acts depending on the speed with which the treadle operates.If, however. the treadle is instantly released as soon as the clutchoperates the guard 17 may not complete its movement or may be withdrawnbefore the ram descends to punch the meta l'. in which case there isstill a possibility of the operators hand either not being re- .movedfrom danger or being allowed to getinto danger again before the ram hasdescended. Accidents may also happen due to other causes as willhereinafter be described. To'supplement the operation of the guard 17,and prevent danger to the hands of the operator during the movement ofthe ram and independently of the guard 17, the guard 20 is provided.This guard is carried on a lever 21 mounted on the same stud 17Connected to this arm 21 is the link .22 carrying the stud 23 on whichis mounted the anti-friction roller 24. This roller engages with the,cam 25 formed in the block 26, mounted upon a bridge 27,

which bridge is supported by the brackets 28 and 29, which brackets areattached to the frame of the press.

Mounted on the stud 23 is the anti-friction roller 30 which is engagedby the actuator 31, which actuator is carried by the ram of the press asfollows; The adjustment slide 32 is attached to the ram of .the press byscrews such as are shown in full and dotted lines in Fig. 4. Theadjustment slide 32 is provided with a groove 36' in which engages theflange 37 on the actuator 31. T UU actuator 31 and the adjustment slideare clamped together by the clamping" bolt 38 which has a head 39 thatengages with the slot 40 on the back of the adjustment slide 32. Theadjustment slide is provided with a slot 41 and the actuator'is providedwith a slot 42. The bolt 38extends through the slots 41 and 42 of theadjustment slide and the actuator and clamps them together and it isobvious that a considerable range .of

adjustment of the actuator 31 on the adjustment slide 32 is therebypermitted. The.

adjustment of the actuator 31- on the adjustment slide determines thetravel of the lever 21 and guard 20.

The operation of the lever 21 and guard I 20 depends on the. operationof the ram of its the press and by setting the actuator .the 1 guard 20can be given along travel or a short one. The time of the operation ofthe guard relative to the movement of the ram is determined by the shapeof thecam 2%.

which cam is so shaped as to cause the, guar 2.0 to sweep in front ofthe die before theram has moved more than one third orone half of itsstroke, thus causing the guard to push aside the hand of the operatorbefore the punch can come into contacta-avi thfit.

As shown in Figs. 1 and 3, the .'.lever 16 is made up of two parts whichare adjusted relatively to each other; and whichwill now be described.

The part 16 is provided with the up turned end 45 and the part16*.isprovided with the upturned end 46. The upturned end 45 is slottedand the upturnedend 46 may be slotted or threaded, the two being clampedtogether by the bolts 47 so that the from the die.

that is in use on punch presses may be used in connection withmyinvention. As there is a co5peration between the clutch and the guard, aparticular form 'of clutch is illustrated in Figs. 9 to 13 inclusive,which clutch may be described as follows: The press isby the latch 63which is normally pressed into engagement with the pin 60 by the spring6-4.- The 'pin 60 is provided with the lug 65 with which the latch 63can engage to hold it back. Mounted on the frame of the press is thelatch 66 which is pressed toward the shaft 67 by the spring-68.- Thislatch carries at its outer end the segment 69 which bears against theperiphery of the collar 70 keyed on the shaft 67. The collar 70 has asegmental recess 71 therein, at the rear side of which is a segmentalpiece made of-extra hard material to take the blow of the clutchdelivered by the pin 60 on the wheel 61. The pin60 is also. made ofextra hard material. The segment 69 is slightly eccentric on its outersurface and has the cam 72 on its inner surface (see Fig. 10). The latch66 is operated from the treadle by the bell crank 73 mounted on theframe of the press. The clutch operates as follows: When the treadle 18isdepremed the bell crank 73 is rockedand the latch 66 is, withdrawn. Asthe wheel 61' turns, the latch 63 carried thereby, .comes into contactwith the outer surface of'the segment 69 and is moved outwardly therebyreleasing the pin )50- which is pressed forward by the spring .62. intothe recess 71, causing the shaft 67 to rotate with the wheel. When thetreadle 18 is released the pin 66 and segment 69- move inward and thecam 65 on thepin 60 rides up on the cam'72 on the segment 69 until it iswithdrawn from the recess 71, after'which it is held back by the latch63. As long as the treadle18 is depressed the latch 66 will remain out.The ram of the press will operate and the guard 17 will .remain in theposition shown in Fig. 1 and with each reciprocation of the ram theguard 20 swings forward and back. The position of the guard 17 .in Fig.1 will be referred to as thesafety position while the position of theguard 20 will be referred to as the danger position.- he operators handis normally placed b'e ween the punch and die in feeding the press andthis will be referred to as the danger position. The guard sweeps thehand horizontally 6r laterally to the right to the so called safetyposition. A

strip of rubber or the other soft material 75 may be put at the forwardedge of each of the guards to cushion the blow that thev the fly wheel61 which rotates continuously power is transmitted from this wheel tothe crank shaft 67 by the clutch. The clutch will remain closed anddrive the crank shaft as long as the treadle 18 is held down. In theordinary, operation of the press the operator first puts a blank on thedie in the press and then presses the treadle down-with his foot tostart the press and then lifts his foot to permit the treadle to riseagain at once,'so that the ram of the press will make a single completestroke and then stop, permitting his hand to be safely placed above thedie to remove the finished piece and insert a fresh blank. The rain willregularly stop because the springs in the clutch will act to open theclutch and disconnect the crank shaft from the iiy wheel. If, however,one or the other of these springs break the clutch will remain closedregardless of the position of the treadle and the ram will keep onoperating until the belt of the press is thrown. In such case the ram isapt to catch the hand of the operator on its next downward stroke whichis unexpected by the operator because he expects the clutch to open andstop theram at the top of its stroke. He,

;, therefore, puts his hand into the press;

above the die to change the stock without any thought of danger. As theram de-. sceuds at once it will catch hishand before he can think toremove it. The press may not operate this way more than once in severalhundred thousand or even several million times and its action when itdoes come is therefore the more unexpected and the more dangerous onthat account. During the second and subsequent movements of the ram dueto the broken clutch the trcadle will be in normal position holding theguard 17 in idle pqosition or danger position. It will tl'ierefore beseen that in such r'ncrgencies the guard 17 is useless because it isdriven by the treadle which remains idle. "if the guard is driven by theram instead of the treadle the breaking of the spring in the clutch willno longer affect the operation of the guard because the guard and rainwill erate together and the guard will knock the hand out of danger eachtime as the ram descends and before it gets down far enough to catch thehand. When the guard is driven by the ram it will move rapidly and willstrike the hani or arm a y heavy blow. This is due to the fact that the17am moves very fast and the guard must move very much faster still ifit is to reach the hand and throw it out from the diebefore the ramcloses in on the die. If these blows are repeated very often the hand orthe arm of the o erator will be severely bruised. It is therefbreobjectionable to depend primarily on the guard driven by the ram toprotect the operators hand. The guard operated by the treadle will pushthe hand out of danger more gently especially as the speed of itsmovement is largely within the control of the operator. Therefore theguard moved by the treadle must be primarily depended on to protect theoperator in the ordinary operation of the press and as. this will notprotect the operator under such abnormal conditions as above described,the guard operated by the ram must also be used to give completeprotection to the operator.

I claim:

1. In a guard for a punch press, the combination of a punch press frame,a plurality of guards pivotally supported from said frame, a ramreciprocating in said punch press, means for driving said ram and meansfor'controlling the operation of said driving means, one of said guardsbeing operated to safety position by said controlling means and theother of said guards being operated to safety position in sequencetherewith by the operation of said driving means.

2. In a punch press the combination of an upright frame and a bed, a ramworking toward and away from said bed, a bridge mounted on said frame, alever pivotally said lever, a stud mounted on said link, a

cam mounted on the bridge with which one end of said studengages, anactuator mounted on the ram with which the other end of said studengages, said stud being adapted to move up and down with the ram andsidewise according to the pitch of the cam causing the lever to swingaccordingly.

3. In a punch press the combination of a frame, a ram mounted toreciprocate in said frame, an adjustment slide fastened to said ram, anactuator adjustably mounted on said slide, a cam mounted on said frameopposite said actuator, a stud engaging with both said actuator and saidcam and adapted to be moved vertically and laterally thereby on thereciprocation of said ram.

4. In a punch press the combination of a. frame, a ram mounted toreciprocate in said frame, an adjustment slide fastened to said ram, anactuator adjustably mounted on said slide, a cam mounted on said frameopposite said actuator, a stud engaging with both said actuator and saidcam and adapted to be moved vertically and laterally thereby on thereciprocation of said ram, a lever and a connection between said studand said lever whercbv the lever is oscillated on the reciprocation ofsaid ram.

mounted on said bridge, a link connected to Y both said uance ed to bemoved vertically and laterally said lever whereby .the reciprocation ofsaid cillate thereon,

thereby on the reciprocation of said ram, a lever and a connectionbetween said stud and the lever is oscillated on ram, said actuatorbeing adjustable to vary the length of the stroke of the lever or itstime-of operation with reference to theoperation of the ram.

6. In a guard for a punch press the combination of a' frame, a levermountedto ostwo sections, each 0 said sections having an upturned end,said sections being clamped aid upturned ends, one

together through of said sections b on the other ends.

ing adjustable laterally press head and dies, of

press to move transversely across the front of the press dies, saiddevice being normally positioned at a. distance to one side" of thevertical center of the front of the press dies and an actuatingconnection between said device and the press head for positivelyoscillating the device across said vertical center of the front of thedies at Copies a ram mounted to reciprocate in said ated press having anation of crank saidlever being made up "of thereby and a frametherefor,

section through saidupturned v side of the operators arms and 7. Thecombination with a power-oper -ated ress having a a sa ety devicepivotally mounted on the each stroke of the press; substantially asdescribed. 7

8. The combination with a power opera guard member pivoted to swingtransversely across the front of the press dies, and an actuating.connection between said member and a part'of the press which moves witheach stroke of the press for positively oscillating both directionsacross the face of the press, said guard member and its. actuatingconsaid guard member in press head and dies, of

nection being normally positioned at a distance laterally from thevertical centerof the front of the press dies, substantially asdescribed.

9. In a guard for a punchipre'ss the combishaft and a' ram driven a.vertically disposed gate mounted on sald frame, connections between saidgate and said xcrank shaft whereby said gate is caused "tomove across infront of said ram and from one thereto whereby the operators be pushedaway from said ram,.as thcshaft operates to push the ram down.

In testimony whereof we affix our'signaof this patent may be obtainedfor five cents each, by addressing th'e Commissioner or latents,

Washington, D 43."

transversely hands will

